Increasing tree cover while losing diverse natural forests in tropical Hainan, China

2013 ◽  
Vol 14 (2) ◽  
pp. 611-621 ◽  
Author(s):  
De-Li Zhai ◽  
Jian-Chu Xu ◽  
Zhi-Cong Dai ◽  
Charles H. Cannon ◽  
R. E. Grumbine
Keyword(s):  
2020 ◽  
Author(s):  
Frederic Achard ◽  
Christelle Vancutsem ◽  
Valerio Avitabile ◽  
Andreas Langner

<p>The need for accurate information to characterize the evolution of forest cover at the tropical scale is widely recognized, particularly to assess carbon losses from processes of disturbances such as deforestation and forest degradation<sup>1</sup>. In fact, the contribution of degradation is a key element for REDD+ activities and is presently mostly ignored in national reporting due to the lack of reliable information at such scale.<br>Recently Vancutsem et al.<sup>2</sup> produced a dataset at 30m resolution which delineates the tropical moist forest (TMF) cover changes from 1990 to 2019. The use of the Landsat historical time-series at high temporal and spatial resolution allows accurate monitoring of deforestation and degradation, from which the carbon losses from disturbances in TMFs can be estimated. A degradation event is defined here as temporary absence of tree cover (visible within a Landsat pixel during a maximum of three years duration) and includes impacts of fires and logging activities.<br>We quantify the annual losses in above-ground carbon stock associated to degradation and deforestation in TMF over the period 2011-2019 by combining the annual disturbances in forest cover derived from the Landsat archive the pan-tropical map of aboveground live woody biomass density (AGB) from Santoro et al.<sup>3</sup> at 100 m. To reduce the local variability within the estimation of AGB values, we apply a moving average filter under the TMF cover for the year 2010. <br>The carbon loss due to degradation is accounted as full carbon loss within a pixel (like a deforestation). The reason is that logging activities usually remove large trees with higher biomass densities than the average value of the disturbed pixel indicated by the pan-tropical maps. To avoid double counting of carbon removal, deforestation happening after degradation is not accounted as carbon loss.<br>Our results are compared with estimates of previous studies that cover different periods and forest domains: (i) Tyukavina et al.<sup>4</sup> provide estimates of carbon loss from deforestation for the period 2000-2012 for all forests (evergreen and deciduous) discriminating natural forests from managed forests, and (ii) Baccini et al.<sup>5 </sup>provide estimates of carbon loss from deforestation and degradation for the period 2003-2014 for both evergreen and deciduous forests.</p><p>In a further step, we will analyze the sensitivity of the results to the input AGB values by applying the same approach to other AGB maps (e.g. Baccini et al. 2012<sup>6</sup>).<br>Finally we intend to use Sentinel-2 data (10 m) for monitoring the location and extent of logging activities and burnt areas and further improve the estimates of carbon losses from forest degradation. </p><p>1. Achard F, House JI 2015 doi 10.1088/1748-9326/10/10/101002<br>2. Vancutsem C. et al. 2019 Submitted to Nat. Geoscience<br>3. Santoro M et al. 2018 doi 10.1594/PANGAEA.894711<br>4. Tuykavina A et al 2018 http://iopscience.iop.org/1748-9326/10/7/074002<br>5. Baccini A et al. 2017 doi 10.1126/science.aam5962<br>6. Baccini A et al. 2012 doi 10.1038/nclimate1354</p>


2017 ◽  
Author(s):  
Ghislain Vieilledent ◽  
Clovis Grinand ◽  
Fety A. Rakotomalala ◽  
Rija Ranaivosoa ◽  
Jean-Roger Rakotoarijaona ◽  
...  

AbstractThe island of Madagascar has a unique biodiversity, mainly located in the tropical forests of the island. This biodiversity is highly threatened by anthropogenic deforestation. Existing historical forest maps at national level are scattered and have substantial gaps which prevent an exhaustive assessment of long-term deforestation trends in Madagascar. In this study, we combined historical national forest cover maps (covering the period 1953-2000) with a recent global annual tree cover loss dataset (2001-2014) to look at six decades of deforestation and forest fragmentation in Madagascar (from 1953 to 2014). We produced new forest cover maps at 30 m resolution for the year 1990 and annually from 2000 to 2014 over the full territory of Madagascar. We estimated that Madagascar has lost 44% of its natural forest cover over the period 1953-2014 (including 37% over the period 1973-2014). Natural forests cover 8.9 Mha in 2014 (15% of the national territory) and include 4.4 Mha (50%) of moist forests, 2.6 Mha (29%) of dry forests, 1.7 Mha of spiny forests (19%) and 177,000 ha (2%) of mangroves. Since 2005, the annual deforestation rate has progressively increased in Madagascar to reach 99,000 ha/yr during 2010-2014 (corresponding to a rate of 1.1%/yr). Around half of the forest (46%) is now located at less than 100 m from the forest edge. Our approach could be replicated to other developing countries with tropical forest. Accurate forest cover change maps can be used to assess the effectiveness of past and current conservation programs and implement new strategies for the future. In particular, forest maps and estimates can be used in the REDD+ framework which aims at “Reducing Emissions from Deforestation and forest Degradation” and for optimizing the current protected area network.


Author(s):  
ZA Riyadh ◽  
MA Rahman ◽  
SR Saha ◽  
T Ahamed ◽  
D Current

Geographical position makes Bangladesh globally as one of the most vulnerable countries to climate change. It is observed that climate change has become a burning issue jeopardizing the agricultural production in the country. Considering the issue, adoption of climate smart agriculture (CSA) is indispensable for mitigating climate change by reducing emissions, capturing the atmospheric carbon and storing it in biomass and soil. The study reviewed the literature to evaluate the potentiality of agroforestry practices as climate smart agriculture to mitigate climate change impacts. Agroforestry has traditionally contributed to climate resilience in Bangladesh by integrating trees and/or crops into different land use practices. Agroforestry systems enhance resilience to climate change through increasing tree cover, carbon sequestration, increasing production, reducing threats to associated crops, creating favourable microclimate to support associated crops, reducing harvest pressure on natural forests, conserving biodiversity and cycling nutrients. Globally 23 countries recognize agroforestry as a mitigation priority, whereas 29 as an adaptation priority. Bangladesh has potential to expand agroforestry practices to mitigate climate change and boost food security. From socioeconomic and ecological point of views as well, agroforestry offers strong potential to evolve climate smart agricultural practices supporting food security, and adaptation and mitigation. Agroforestry practices should increase in climate vulnerable agroecosystems of Bangladesh. Int. J. Agril. Res. Innov. Tech. 11(1): 49-59, June 2021


Author(s):  
K. E. Mothi Kumar ◽  
R. Kumar ◽  
R. Kumar ◽  
R. Bishnoi ◽  
R. S. Hooda ◽  
...  

<p><strong>Abstract.</strong> Haryana state is an intensively cultivated state, and deficient in natural forests. One of the mandate of Haryana Forest Department (HFD) is to afforest for maintenance of environmental stability and restoration of ecological balance affected by serious depletion of forests, woodlands and water, and to increase tree cover in the state. National Forest Policy (1988) has set a goal to bring one third of Country’s area under forest and tree cover. Stock and dynamics of Trees Outside Forests (TOF) along with natural forests need to be understood holistically to appreciate the ecosystem services e.g., timber and non-wood products as tangible benefits along with services like carbon, water and weather moderation. The present study has attempted to demonstrate the utility of High Resolution Worldview-II (WV) satellite data (ortho rectified) that offeres immense scope to analyze the strip forests in Hisar district (Haryana, India). The study area Adampur Range (Hisar District) lies between the north latitudes 29&amp;deg;0′52.229″ to 29&amp;deg;25′6.746″ and east longitudes 75&amp;deg;14′0.266″ to 75&amp;deg;45′11.093″ with a total geographical area of about 1092.04<span class="thinspace"></span>sq.<span class="thinspace"></span>km. The adopted methodology involves onscreen digitization of the strip forest areas in the Adampur range (Hisar Distirct). The ToF formation identification and delineation includes the forest land besides roads, river, streams, canals, distributaries and railway lines etc. The shape files were converted into .kml files and overlaid on the Google Earth data for validation. An attempt has been made to compare the area difference between the Haryana Forest Department (HFD) notification details with that of the digitized strip forest lands. It was observed that the surveyed forest area is found to be 1717.37<span class="thinspace"></span>ha. against the notified forest area of 1714.45<span class="thinspace"></span>ha. showing a difference of 2.92<span class="thinspace"></span>ha. approximately in the studied beat boundaries.</p>


2020 ◽  
pp. 1-15
Author(s):  
GIANPASQUALE CHIATANTE ◽  
ZENO PORRO ◽  
ALBERTO MERIGGI

Summary Farmland birds represent a large proportion of European avifauna, and the populations of several species have suffered a dramatic decline in recent decades. Among these species, the European Turtle Dove Streptopelia turtur has undergone rapid decline in much of its European range. Therefore, the main aims of this research are to estimate the population density of the Turtle Dove and to investigate its habitat use at home range scale in an intensively cultivated agroecosystem in northern Italy. In the 2015 breeding season we carried out turtle dove counts from 372 point-counts, randomly allocated following a stratified cluster sampling design. The density was estimated by distance sampling, whereas the habitat suitability was assessed by Resource Selection Probability Function. In particular, we followed a presence vs availability approach, using binary logistic regression and the Information-Theoretic approach. During fieldwork, 76 observations of Turtle Dove were collected and a density of 5.0 pairs/km2 was estimated. The Turtle Dove inhabits areas with high tree cover, either semi-natural forests or tree plantations, as well as areas with many shrubs and hedgerows. On the other hand, areas with a high proportion of crops, such as paddyfields, maize, and winter cereals are avoided. For the species’ conservation, it is necessary to maintain a combination of habitat features with suitable nesting and feeding areas, as the degradation of either of these may reduce Turtle Dove populations.


Author(s):  
Stephen Graham ◽  
Hanna Julia Ihli ◽  
Anja Gassner

AbstractAddressing interconnected social and environmental issues, including poverty, food security, climate change, and biodiversity loss, requires integrated solutions. Agroforestry is a sustainable land use approach with the potential to address multiple issues. This study examined the tree cultivation behavior of smallholder farmers in the Mt. Elgon region of Uganda. We examined the proportion of indigenous tree species added to or removed from agricultural land and the reasons for farmers’ decisions in this regard. We found that farmers overwhelmingly planted exotic species, limiting the possible benefits for the conservation of biodiversity from a suggested re-greening of the region. Indigenous trees were cultivated in low numbers and dominated by a handful of species. Opportunities to help farmers increase the number and variety of indigenous trees on their land were found among smaller-scale coffee farmers and in the protection of natural forests from which indigenous trees propagate into the wider landscape.


2020 ◽  
Vol 15 (12) ◽  
pp. 124055
Author(s):  
Adison Altamirano ◽  
Alejandro Miranda ◽  
Paul Aplin ◽  
Jaime Carrasco ◽  
Germán Catalán ◽  
...  

2019 ◽  
Vol 48 (3) ◽  
pp. 417-425
Author(s):  
Md Khayrul Alam Bhuiyan ◽  
Md Akhter Hossain ◽  
Abdul Kadir Ibne Kamal ◽  
Mohammed Kamal Hossain ◽  
Mohammed Jashimuddin ◽  
...  

A study was conducted by using 5m × 5m sized 179 quadrates following multistage random sampling method for comparative regenerating tree species, quantitative structure, diversity, similarity and climate resilience in the degraded natural forests and plantations of Cox's Bazar North and South Forest Divisions. A total of 70 regenerating tree species were recorded representing maximum (47 species) from degraded natural forests followed by 43 species from 0.5 year 39 species from 1.5 year and 29 species from 2.5 year old plantations. Quantitative structure relating to ecological dominance indicated dominance of Acacia auriculiformis, Grewia nervosa and Lithocarpus elegans seedlings in the plantations whereas seedlings of Aporosa wallichii, Suregada multiflora and Grewia nervosa in degraded natural forests. The degraded natural forests possess higher natural regeneration potential as showed by different diversity indices. The dominance-based cluster analysis showed 2 major cluster of species under one of which multiple sub-clusters of species exists. Poor plant diversity and presence of regenerating exotic species in the plantations indicated poor climate resilience of forest ecosystem in terms of natural regeneration.


2012 ◽  
pp. 109-134
Author(s):  
P. S. Shirokikh ◽  
A. M. Kunafin ◽  
V. B. Martynenko

The secondary birch and aspen forests of middle stages of succession of the central elevated part of the Southern Urals are studied. 4 subassociations, 1 community, and 7 variants in the alliances of Aconito-Piceion and Piceion excelsae are allocated. It is shown that the floristic composition of aspen and birch secondary forests in the age of 60—80 years is almost identical to the natural forests. However, a slight increase the coenotical role of light-requiring species of grasslands and hemiboreal forests in the secondary communities of the class Brachypodio-Betuletea was noticed as well as some reduction of role the shade-tolerant species of nemoral complex and species of boreal forests of the class Vaccinio-Piceetea. Dominant tree layer under the canopy of secondary series is marked by an active growth of natural tree species.


2008 ◽  
Vol 159 (4) ◽  
pp. 80-90 ◽  
Author(s):  
Bogdan Brzeziecki ◽  
Feliks Eugeniusz Bernadzki

The results of a long-term study on the natural forest dynamics of two forest communities on one sample plot within the Białowieża National Park in Poland are presented. The two investigated forest communities consist of the Pino-Quercetum and the Tilio-Carpinetum type with the major tree species Pinus sylvestris, Picea abies, Betula sp., Quercus robur, Tilia cordata and Carpinus betulus. The results reveal strong temporal dynamics of both forest communities since 1936 in terms of tree species composition and of general stand structure. The four major tree species Scots pine, birch, English oak and Norway spruce, which were dominant until 1936, have gradually been replaced by lime and hornbeam. At the same time, the analysis of structural parameters indicates a strong trend towards a homogenization of the vertical stand structure. Possible causes for these dynamics may be changes in sylviculture, climate change and atmospheric deposition. Based on the altered tree species composition it can be concluded that a simple ≪copying≫ (mimicking) of the processes taking place in natural forests may not guarantee the conservation of the multifunctional character of the respective forests.


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